Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 09 May 2003 00:35:32 -0700 | From | Ulrich Drepper <> | Subject | hammer: MAP_32BIT |
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To allocate stacks for the threads in nptl we currently use MAP_32BIT to make sure we get <4GB addresses for faster context switching time. But once the address space is allocated we have to resort to not using the flag. This means we have to make 2 mmap() calls, one with MAP_32BIT and if it fails another one without.
It would be much better if there would also be a MAP_32PREFER flag with the appropriate semantics. The failing mmap() calls seems to be quite expensive so programs with many threads are really punished a lot.
- -- - --------------. ,-. 444 Castro Street Ulrich Drepper \ ,-----------------' \ Mountain View, CA 94041 USA Red Hat `--' drepper at redhat.com `--------------------------- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux)
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